Telephone-transmitter.



N. TANNAKA.

TELEPHONE TRANSMITTER.

APPLICATION FILED NOV. 3. I916.

Patented Dec. 24, 1918,

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NAHO TANNAKA, OF NEW YORK, N. Y.

TELEPHONE-TRANSMITTER.

Application filed November 3, 1916.

or the vibrator -is'kept away from direct contact with hard fixed parts and a flexible sheeting (or auxiliary vibrators), except at or with parts where such contact, if any, hinders only imperceptibly the required movement of the vibrator, so that certain undesirable effect upon the vibrator resulting from such contacts is minimized, and one or more of carbon cells having a large combined area of electrode surface are employed.

The principal objects of my invention are, first, to minimize distorting effect in the sound transmission as far as the transmitting apparatus is concerned; in other words, to faithfully translate vocal waves into electrical impulses, or at any rate to transmit sound vibration more agreeably than heretofore possible; second, to increase the current carrying capacity of the apparatus so that heavy currents may be advantageously employed or the apparatus, may be exposed to higher voltage currents than heretofore possible without injury thereto: and third, to increase the resistance variability ofv the apparatus in high resistance circuits. The further object is to provide apparatus of this class in which the granular carbon will not become packed.

With the above and other objects in View, my invention comprises certain detail of construction and arrangement of parts, as will be hereinafter more fully described, illustrated and claimed.

The invention will be best understood from the following description taken in connection with the accompanying drawings as reference, forming a part of this specification. However, I desire to have it understood that the apparatus herein shown is merely illustrative, as the best embodiments of'my invention as now thought, and that therefore I do not confine myself to any strict conformity to the showing of the draw- Specification of Letters Patent.

Patented Dec. 24, 1918.

Serial No. 129,291.

ings, but such changes and modifications may be made, when desired, as to fall within the scope of the invention as claimed.

In the drawings, similar characters of reference indicate correspondingparts, and in Figurel is-a vertical sectional view of a telephone transmitter embodying my invention,

Fig. shows another embodiment thereof being'a similar view, and

Fig. 3 is an enlarged view,showing the flexible connection of parts in Fig. 1.

Referring-to the drawings, A designates a vibrator proper preferably of hard rubber or other comparatively light'material, which correspondsto a diaphragm in an ordinary transmitter, but has the freedom of vibration at its peripheral portion as well as at the center.

In Figs. 1 and 3, the vibrator A'rigidly carries as a part thereoffront electrodes B, each of which iselectroplated and soldered toa shank Z) having a screw stem cthat engages with small nuts 6, 6 preferably of light material on opposite sides of the vibrator. The screw stems 0 pass through the perforations of a flexible sheeting C, such as of mica or celluloid, and the sheeting G is yieldingly held between ring washers or cushions I), E of felt or rubber or the like, which are in turn held between the nuts 6 and shanks I). The purpose of the employment of these cushions is to eliminate or minimize the di'stortive effect, on the vibrator, of the natural vibration of the sheeting C.

A back electrode part F in a plurally cup-- shaped or depressed form, having back electrodes G at the cup bottoms, is disposed in such manner that each of the front electrodes B confronts in parallel to the back electrode in a cup, leaving enough marginal space around its peripheral edge. The back electrode part proper may be made of metal or carbon, but is preferably of insulating material, particularly, when desired to have each carbon cell insulated from the others so that the cells can be conveniently connected in series. The sheeting G is clamped ily understood from the drawings. The peripheral edge of the sheeting C is also clamped between a front piece H and a guard ring 2' as shown. The front piece has a large aperture to receive a mouth piece J.

The spaces between the front and back electrodes are partly or fully filled with carbon granules or balls I, the ring cushions E sealing the spaces to prevent the carbon from leakage.

The necessary relative movement between the front and back electrodes is permitted partly by the flexing of the sheeting G, and partly by the yieldin of the cushioning washers D, E. It is o vious that the double provision of flexibility dr yieldability is desirable in order to lessen the resistance to the vibration of the vibrator and to partially relieve the stresses on the sheeting, and at the same time to make the cushions act as damping means for damping the vibrations of the vibrator, but that by employing a substantially inflexible sheeting, the cushions alone may be assigned to perform the function when desired.

The circumferential edge of the vibrator is preferably, though not necessarily, padded by a soft rubber band 9 to nearly close the air gap at that place. The terminals of the cells are led out to the screws 7, f.

In Fig. 2, the arrangement of parts is reverse to that of Fig. l, the vibrator part taking the form of the back electrode part of Fig. 1, and vice Versa. A indicates a plurally cup-shaped vibrator having front electrodes B attached to the bottoms. Back electrodes G are secured to shanks with screw stems c which are secured to a back plate F by means of nuts 6, e. The vibrator and the back plate are yieldingly connected by a sheeting C and cushions D, E, the sheeting being attached to the vibrator by means of a central screw f and a light 001- lar it over the periphery. The back plate is preferably made of flexible material, and is secured to the casing H which has small openings at the front for admitting vocal waves to enter there-through. It is needless to state that the front or vibrator partshould be made as light as possible to have least possible inertia thereof.

In the present instances, I have illustrated the forms having four variable resistance cells; however, the number of the cells may be varied, when so desired, and even a single cell may be employed in an instance, the cushions D, E may be applied on opposite sides of the sheeting or mica auxiliary diaphragm of a solid back transmitter.

From the foregoing description taken in connection with the accompanylng drawings, in which I have illustrated the apparatus and the arrangements of parts as the best embodiments of my invention, the advantage of the construction and arrangements of parts and the methods of operation will be readily apparent to those skilled in the art to which this invention appertains.

Having thus described the invention, I claim:

1. In a telephone transmitter, an elastic connecting medium for opposing electrode bearers, comprising a sheeting, and cushioning washers disposed on opposite sides of the sheeting and held therewith together by one of the said bearers, the sheeting being rigidly attached to the other said bearer.

2. In a telephone transmitter, means for elastically connecting front and back electrode bearers, comprising a flexible sheeting attached to one of the said bearers, and yielding members between the sheeting and the other bearer, attaching means of the latter holding the sheeting and the yielding members together. 7

3. In a telephone transmitter, a yielding connection medium, comprising a sheeting and cushions for opposing electrode bearers, the'said sheeting being rigidly attached to one of the said bearers and yieldingly to the other through the said cushions which are held between the sheeting and the lat- I ter bearer.

4. In a telephone transmitter, a mounting for avibrator, comprising means connecting the vibrator to a front electrode, a sheeting secured to a support, and cushions disposed on opposite sides of the sheeting and held therewith together by the said means.

5. In a telephone transmitter, the combination with front and back electrode units, and a variable resistance medium between the said units; of a sheeting, and yielding washers on opposite sides of the sheeting, said sheeting being attached to one of the said units and elastically connected to the other unit through the said washers.

6. In a telephone transmitter, the combination of a sheeting and cushions on opposite sides of the sheeting; with two opposing electrode parts, one directly and the other-through the said cushions, attached to the sheeting, and granular carbon between the said electrode parts, all wholly supported by the sheeting.

7. In a telephone transmitter, two relatively movable parts, one having cup-shaped portions, an elastic sheeting attached to the cupshaped portions and yieldingly to the other of said parts, and granular carbon between the said parts.

8. In a telephone transmitter, a supporting sheeting, cushions, two relatively movable members attached to the sheeting, one directly "and the other through said cushions, and granular carbon between the said members.

9. In a telephone transmitter, the combination with a casing, front and back electrode units, and variable resistance mediuni; of cushions, and a sheeting connectsheeting being attached to the other unit, 10 ed to the casing and one of the said units, and granular carbon between the units. and yieldingly attached to the other unit In testimony whereof I aifix my signature through the cushions. in presence of two subscribing witnesses.

10. In a telephone transmitter front and back electrode units, a casing flexibly con- NAHO TANNAKA nected to the back unit, a sheeting, cushions Witnesses:

on opposite sides of the sheeting held there- Y. HOGAKU, with together by one of the said units, the b H. M. NAKAGAWA.

' Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, I). 0. 

